Engine-indicator.



Lil

UNITED STATES PATENT OFFICE.

HUGO ALBERT CARL AUGUST l/VILHELM MAIHAK, OF HAMBURG, GERMANY.

ENGINE-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 703,434, dated July 1,1902.

Application filed July 8,1901- Serial No. 67AM. (No model.)

To ctZZ whom, it may concern:

Be it known that I, HUGO ALBERT CARL AUGUST WILHELM MAIHAK, a citizen ofthe German Empire, and a resident of Hamburg, Germany, have inventedcertain new and useful Improvements in or Relating to Engine-Indicators, of which the following is a specification.

The stopping means hitherto used in connection with indicator-drums withthe indicator-cord in stretched position necessitates the arrangement ofspecial devices for stretching the cord (double spring-casings or thelike) which oscillate together with the moving drum. Owing to thisarrangement, however, the weight of the oscillating mass of the drum isincreased, which weight, however, should be kept as low as possible, andby this increase the precision of the diagram is impaired.

In the indicator device which forms the object of the present inventionthe arresting action of the drum is simplified, so that the weight ofthe drum or of the oscillating mass is not increased, but is, on. thecontrary, diminished, while at the same time the device can be used forengines with very high number of revolutions. This decrease of weight iseffected by the arrangement of a single spring for thepaper-drum when inmotion as well as when arrested. This device can be made in variousmodifications, one of which is represented in the accompanyingdrawings,in which Figure 1 is a vertical section of the drum in operativeposition. Fig. 2 is the same in arrested position.

A grooved disk 0, rotatively mounted upon the fixed druni-shaftaandwound up bymeans of the coiled spring Z), carries a central cone d,about which is arranged a cone-seat u on the lower part to of thepaper-receiving drum Z. The drum 75, together with the upper portion,which for the purpose of a better guidance can beprovided with a boss o,is loosely and rotatively mounted upon an adjusting screw-threadedsleeve 9. The latter is provided with a button h and engages the threadsf of the central shaft a, a screw 7c being provided to limit the extentof movement of the screw-threaded sleeve g.

In the grooved disk 0 a spring-pin Zmoves in a box or recess t', saidpin engaging with an opening at in the cone seating on the lower part ofthe drum, while the downward-projecting portion of the box or pin casing'Z in striking against a stud m serves for limiting the reciprocatingmovement of the grooved disk. Fig. 1 shows the drum t coupled with thegrooved disk 0, in which case the drum moves, together with said grooveddisk. If it is desired to stop the drum for the purpose of attaching afresh indicator-paper, the screw is rotated to the left by means of thebutton h, thereby releasing the drum from the cone d, as well as fromthe spring-pin Z, Fig. 2, and stopping its rotation, while the grooveddisk continues to oscillate and to stretch the indicator-cord. When itis required to again couple the drum with the grooved disk 0, the screw9 is turned to the right and therefore presses the drum downward uponthe cone (Z. The reciprocating grooved disk 0 brings the pin Z oppositeto the opening an, thus causing it to engage with the latter andsecuring the drum in the corresponding position upon the grooved disk.The spring-pin Z could also be arranged upon the drumt and engage withthe grooved disk. In this case the lattermust be provided with asuitable abutment for limiting the extent of movement.

I claim 1. In an engine-indicator, the combination of aspring-influenced pulley having a conical hub, with a vertically-movablepaper-receiving drum having a coned seat adapted to engage said hub,substantially as specified.

2. In an engine-indicator, the combination of a spring-influenced pulleyhaving a conical hub, with a paper-receiving drum having a coned seatadapted to engage said hub, a spring-pin coupling between pulley and drum, a vertically-movable adjusting-nut supporting the drum, and a fixedbolt engaged by the nut, substantially as specified.

Signed by me at Hamburg this 15th day of June, 1901.

HUGO ALBERT CARL 7 AUGUST WILHELM MAIHAK. Witnesses:

A. GoPPs, E. H. L. MUMMENHOFF.

